To commemorate the 15th anniversary of the Aria the Scarlet Ammo anime on April 15th, the production of a new short anime has been green-lit.
The series is based on the popular light novel written by Chugaku Akamatsu, which has surpassed 9 million copies in total circulation. Detectives who use armed force to resolve problems and combat worsening crime are known as "Butei." Kinji Tōyama was a student at Butei High School, a training facility for Butei, but due to a certain incident, he was planning to quit Butei High and transfer to a regular school.